A PROTEIN WITH KINASE AND PHOSPHATASE-ACTIVITIES INVOLVED IN REGULATION OF TRICARBOXYLIC-ACID CYCLE
A PROTEIN WITH KINASE AND PHOSPHATASE-ACTIVITIES INVOLVED IN REGULATION OF TRICARBOXYLIC-ACID CYCLE
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DOI：
10.1038/300458a0
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发表时间：
1982-01-01
期刊：
影响因子：
64.8
通讯作者：
KOSHLAND, DE
中科院分区：
文献类型：
--
作者：
LAPORTE, DC;KOSHLAND, DE
磷酸化-去磷酸化反应作为一种调控形式，在我们对细胞过程的理解中扮演着越来越重要的角色。磷酸化-去磷酸化反应是对照中第一个共价修饰的例子，几乎存在于所有类型的细胞过程中，包括细胞成分的合成、代谢途径甚至基因表达1。由于发现致癌病毒编码的一些蛋白质显然参与了磷酸化反应2，3，它被认为是日益重要的结果。为了更好地理解这些过程的基本原理，我们研究了异柠檬酸脱氢酶(IDH)的磷酸化在调节三羧酸(TCA)循环和乙氧基酸旁路之间的分支点中的作用。我们在此报道，在提纯磷酸酶和磷酸酶的过程中，我们发现了两个令人惊讶的现象--激酶和磷酸酶的活性似乎与同一种蛋白质有关，而磷酸酶的活性对ATP有绝对的要求。
Phosphorylation–dephosphorylation reactions as a form of regulatory control are assuming increasing importance in our understanding of cellular processes. The phosphorylation–dephosphorylation reaction was the first example of covalent modification in control and has been found to be present in almost every type of cellular process including synthesis of cell constituents, metabolic pathways and even gene expression1. It has assumed increasing importance as a result of the finding that some proteins coded for by carcinogenic viruses apparently are involved in a phosphorylation reaction2,3. To better understand the principles underlying these processes, we have studied the role of phosphorylation of isocitrate dehydrogenase (IDH) in the regulation of the branch point between the tricarboxylic acid (TCA) cycle and the glyoxylate bypass. We report here that in the process of purifying the kinase and phosphatase, we made two surprising observations—the kinase and phosphatase activities appear to be associated with the same protein, and the phosphatase activity has an absolute requirement for ATP.